It's enrollment time for Affordable Care Act health insurance, but you may not know it because the Trump administration isn't doing much to encourage people to sign up for coverage. Critics say the president's actions are even making health insurance more expensive and harder to get. But despite the headlines, many people may still be able to get affordable insurance on the exchanges. Joining us now is NPR health policy correspondent Alison Kodjak to discuss what's happening in the Obamacare marketplaces and how to shop for a plan. Hey, Alison.

ALISON KODJAK, BYLINE: Hi, Lulu.

GARCIA-NAVARRO: All right. Open enrollment started last week. What are the biggest differences between this year's sign-up period and last year's?

KODJAK: So the biggest difference people are going to see is that this year's sign-up period is much shorter. It's only six weeks long, which is half as long as last year. So if you're buying insurance on the federal exchange, healthcare.gov, you have to pick it out before December 15. The other thing is there's no advertising, no television advertising from the government. Last year, they spent a lot of money trying to get people to know what's going on and to sign up. And there's also fewer navigators. These are the people who are out there who are certified and trained to help people choose an insurance policy that's best for them and help them actually get enrolled.

GARCIA-NAVARRO: So kind of like adviser?

KODJAK: Advisers, yeah.

GARCIA-NAVARRO: OK. There have been a lot of headlines saying insurance premiums are up. We've heard them all saying these are going to be very expensive plans. But you've reported that there are some deals to be had out there. Can you explain what's going on?

KODJAK: Sure. So the way that the Affordable Care Act works is insurance companies set prices, but then the government gives most people subsidies. When premiums go up so do the subsidies because the way the law is designed is to keep people's out-of-pocket costs constant. And so what you might find if you're shopping and you have qualified for a subsidy before is that your subsidy will go up with the insurance. And in addition, because of one of the weird things going on in the law and in the politics of D.C., a lot of these insurance companies have piled those increases in premiums onto very specific plans. So if you shop outside those specific plans, which are called Silver plans, you might even get a better deal than you got last year.

GARCIA-NAVARRO: So maybe for some people what they pay out of pocket could go down or at least stay the same.

KODJAK: It could stay the same. It could go down. And you know, I have a study here by a company called Avalere Health, which does really great analysis on the health care market. And they say in most counties across the country, there's at least one plan available to low-income people for free.

GARCIA-NAVARRO: Oh, OK. What about people who don't get subsidies, though? How many are there, and what are they going to find?

KODJAK: Well, those are the people who are really going to have trouble. There are about 5 million people who buy insurance on the individual market and don't get subsidies. Now, for some of those people, they are ill. They have ongoing illnesses. They're going to want the insurance no matter what it costs. But for the others, they might find that it's too expensive. And they might not want to buy it. What some advisers are saying is they might want to look off the exchanges instead of on the exchanges because, as I said, the insurance companies were piling a lot of their price increases on these very specific plans that are only sold on the exchange. So they might be able to get a comparable policy if they buy it outside the Affordable Care Act exchange.

GARCIA-NAVARRO: We mentioned in the beginning that President Trump hasn't been doing much to promote this open-enrollment period, but another president is. Barack Obama made a cameo this week. What did he have to say?

KODJAK: Yeah, he put out a little video via Twitter - and he's got a lot of Twitter followers - where he basically encouraged people to sign up for insurance, to get out there and shop. And he also pointed out that, because of the Affordable Care Act, people who have pre-existing conditions can still get insurance and that women can get insurance at the same price as men. So I think he was trying to, at least, defend the law that bears his name a little bit out there.